Package



May 22, 1951 3nventor Gttorncg Patented May 22, 1951 PACKAGE James E.Snyder, Akron, Ohio, assignor to Wingfoot Corporation, Akron, Ohio, acorporation of Delaware Application July 26, 1948, Serial No. 40,659

1 Claim.

This invention relates to a new bag structure in which the walls areeach at least two plies thick. In each wall, at least two of the pliesare so composed that, although individually heatscalable, they do notform a strong bond when heated in pressure contact with one another. Ifthe bags are double-walled, the edges of the outer wrapping materialprotrude at the mouth of the bag beyond the edges of the inner wrappingmaterial, and the respective materials are heatsealed to themselves. Thebond of the outer material engages the bond of the inner material andprevents the bag of the inner material from slipping out of the bag ofthe outer material, If there is more than one seam between therespective wrapping materials at the mouth of the bag there may be aplurality of such bonds between the outer material which engage bonds ofthe inner material and hold the inner bag in place. If there are morethan two plies in the walls of the bag there will be at least one suchbond of outer material engaging a bond of inner material to prevent aninner bag slipping out of an outer bag. Ordinarily the walls will be nothicker than two plies and the invention will be more particularlydescribed with reference to such a structure.

There are various heat-sealable wrapping materials on the market, suchas rubber hydrochloride film, film of copolymer of vinyl chloride andvinylidine chloride, polyethylene lm, coated cellophane, (regeneratedcellulose) coated metal foils, etc. Such wrapping materials, althoughreadily heat-scalable to themselves, do not form a good bond whenbrought into heated pressure contact with one another. Thus, althoughtwo plies of rubber hydrochloride lm may readily be sealed to oneanother if pressed together at an elevated temperature, and similarly,two plies of coated cellophane may similarly be'heat-sealed together,rubber hydrochloride lm does not form a good bond when brought intoheated pressure contact with coated cellophane.

The invention will be further described in connection with theaccompanying drawings Fig. 1 is a plan view of a bag made of two pliesof plastic wrapping material having different heat-sealing properties;

Fig. 2 is an enlarged section on the line 2--2 of Fig. 1;

Fig. 3 is an enlarged section on the line 3 3 of Fig. 1;

Fig. 4 is a plan view of abag of diierent construction;

Fig. 5 is an enlarged section on the line 5-5 of Fie. 4;

Figs. 6 and 7 are plan views of bags of still different constructions;and

Fig. 8 is a section on the line 8-8 of Fig. 7.

Although the invention is described more particularly with respect tobags made of rubber hydrochloride lm and coated cellophane, it is to beunderstood that the bags of this invention may be formed of otherheat-scalable wrapping materials which are each heat-sealable tothemselves (i. e., they are homo-heat-sealable) but are notheat-scalable to one another (i. e., they are not hetero-heat-sealable).The coated cellophane referred to herein is cellophane coated with aheat-scalable coating.

Fig. l illustrates a bag made from two sheets of wrapping material byfolding the sheets at the left edge of the bag. The inner sheet 5 isrubber hydrochloride nlm and is folded along the line 6. The outer sheet'l is coated cellophane and is .folded at the line 8. The outer sheet iextends beyond the inner sheet along the right-hand side at 9 and alongthe bottom at lil. The edges of the inner sheet extend only to the lineIl along vthe side and only to the line l2 at the bottom.

Similarly, at the top the inner sheet extends only to the line I3,whereas the outer sheet extends to the line I4. The sheets are unitedalong the right-hand side and bottom edges in the stippled areas by asingle application of heat and pressure. This produces an area l5 of thebonded outer sheet which engages the bond formed by union of the edgesof the inner sheet. This sealed area I5 holds the inner bag in place andprevents it from slipping out of the outer bag.

In some cases the simultaneous sealing of two sheets results in enoughcling between the dissimilar materials to prevent the inner bag fromslipping out of the outer bag without the aid of the bonded area I5, butin all such cases the bonded area l5 gives assurance of non-separationof the component parts of the bag.

Many factors influence the position of the two or more sheets used inthe walls of the bag. In general, it is desirable to place on theoutside the material with the higher sealing temperature. Also,generally speaking, the material that forms the strongest bond should goon the inside. However, such factors are not generally controlling. Ifone of the wrapping materials is toxic or odorous and the material to bepackaged is sensitive to either of these conditions, that will becontrolling. Also the nature of the material being packaged and theexternal conditions to which it is to be subjected must be given carefulconsideration. For instance, if rubber hydrochloride film and coatedcellophane are to be used in the package, sometimes one will be on theoutside and sometimes the other. If the material to be packaged isaqueous or contains an aqueous ingredient the cellophane cannot be usedinside, but must be used outside. On the other hand, if the material tobe packaged is dry, but the package may come in contact with water thecellophane must be used on the inside. If the product and the externalconditions are such that either ply may be used on the inside or outsideit is advantageous to place the cellophane on the outside, because insealing the cellophane a higher temperature may be used than with rubberhydrochloride without melting, thus assuring a better inner seal.

In forming a bag with the rubber hydrochloride on the inside, asillustrated, the rubber hydrochloride sheet Will be smaller thanthefsheet of coated cellophane. The sheet of the cellophane extendsbeyond the edge of the rubber hydrochloride lm on all four sides. Thetwo plies of lm are then doubled along the middle, along the lines 8 and8 respectively. Then by a hot iron or other hot sealing instrument thebottom and side are heated over the stippled areas.

Thus, the rubber hydrochloride lm is sealed to itself inside the coatedcellophane which is simultaneously sealed to itself outside the rubbei`hydrochloride film, although coated cellophane cannot be sealed torubber hydrochloride lm to form a satisfactory bond.

The resulting bag, as illustrated in Figs. 1 to 3, is very satisfactoryfor the packaging of a great variety of materials. When the bag isfilled it may be sealed across the top by a wide heat-seal which lies onboth sides of the edge I3 of the inner film. The inner surface of thebag possesses all of the advantages of a bag of rubber hydrochlorideiilm, and the outer surface possesses all the advantages of a bag ofcoated cellophane. By selection of films, bag structures are obtainable,having a variety of packaging and keeping properties.

The bag need not be formed by doubling the two sheets. Instead, thesheets may be folded at about a quarter of their width from each edge,forming the type of bag illustrated in Figs. Ll and 5. Here the innersheet 29 and outer sheet 2i are folded at 22y and 23 respectively. Theouter sheet protrudes beyond the inner sheet at 24 at the mouth of thebag. The sheets are sealed to themselves simultaneously in the stippledareas 25 and 26 at the bottom of the bag and in the stippled areas 2'!and 28 in the middle of the side, the reference numerals indicating thebonds of the inner and outer sheets, respectively. The bond 29 of theprotruding outer sheet at the mouth of the bag engages the bond 2-1 ofthe inner sheet lying inwardly of it, and holds the inner bag in place.

Fig. 6 illustrates a different bag construction in which two smallersheets of rubber hydrochloride lm y3l) are placed within two largersheets of coated cellophane 3l, the edges of the rubber hydrochloridefilm coinciding and the edges of the coated cellophane coinciding. Bothside edges of the sheets and the bottoms of the sheets are then sealedlover the areas indicated by stippling, the numeral 32 indicating thebond of the inner sheet and the numerals 33 the bond of the outer sheet.Thus the two plies of rubber hydrochloride lm are united to one anotherat the same time the two plies of coated cellophane are united to oneanother. The seals 34 of the coated cellophane engage the seals 32 ofthe rubber hydrochloride lm at each side of the finished bag and keepthe bag of rubber hydrochloride lm from slipping out of the outer bag ofcoated cellophane.

The bag shown in Figs. 7 and 8 resembles somewhat the bag shown in Fig.1 because both bags are made from but two plies of material and in theconstruction of both bags the plies are doubled along their centerline.In the bag of Figs. 7 and 8, instead of heat-sealing along adjoiningedges, as illustrated in Fig. 1, the opposite edges of the big aresealed. The stippled areas 40 illustrate the heat-seal of thehubberhydrochloride iilm and the stippled areas 4I illustrate the sealof the coated cellophane. The seal of the coating on the cellophaneextends inwardly over the rubber hydrochloride seals at both sides ofthe top of the bag at 42, thus preventing the inner bag from beingdisplaced from the outer bag. The outer sheet protrudes beyond the innersheet at 43 across the top of the bag to permit sealing the sheets tothemselves by a single seal, to close the bag after lling.

Although in the drawings the edge of the inner sheet at the mouth of thebig is shown as perfectly straight, modications within the scope of thisinvention include the use of a sheet with an edge that is not straight.For example, if the top edge of the inner sheet in Fig. 7 slopesdownwardly over the heat-sealed areas 40 the inner bag is held moresecurely within the outer bag than if the top edge of the inner sheet isperfectly straight.

There are many constructions in which it is desirable to use wrappingmaterials of different composition. For example, different wrappingmaterials are impervious to different gases and vapors. A combination oftwo lms gives protection not obtained by two plies of film of the samecomposition. Furthermore, different materials have different strengths,different solubilities, and their other physical properties differ. Forexample, one may combine an inner ply of a material with desirablesolvent properties, with an outer ply of a material having desirableabrasion-resisting properties or desirable strength. A great variety ofbag structures is thus made possible.

What I claim is:

An empty and open double-walled bag, each wall being composed ofdifferent wrapping materials, the respective materials beinghomoheat-sealable but not hetero-heat-sealable, and at the end of a seamof the respective materials leading to the mouth of the bag aheat-sealed area of the outer wrapping material protruding beyond theseam between edges of the inner Wrapping materia-l in both the directionof the mouth of the bag and the direction oi the outer edge of the seam,the seal of the outer material engaging the seal of the inner materialat the end of the seem so as to prevent the bag ele'- ment of the innermaterial from slipping out of the bag element oi the outer material.

JAMES E. SNYDER.

REFERENCES CITED The'following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,128,904 Belcher Sept. 6, 19382,176,499 Hoppe et al. Oct. 17, 1939 2,177,894 Lakso Oct. 31, 19392,234,065 Vogt Mar. 4, 1941 2,254,510 Bergstein Sept. 2, 1941 2,257,823Stokes Oct. 7, 1941 2,298,522 Waters Oct. 13, 1942

